1. Field of the Art
This invention relates to an ACF (Anisotropic Conductive Film) tape feeder machine and a method for feeding ACF tape, suitable for use in feeding and bonding ACF on substrate plates, for example, suitable for use in a liquid crystal display panel fabrication process for bonding ACF on a transparent substrate plate of a liquid crystal cell for the purpose of mounting driver electronics thereon.
2. Prior Art
For example, driver electronics including a plural number of IC devices are connected to at least two side edges of a transparent substrate of a liquid crystal display panel. In some cases, the driver electronics are constituted by IC devices themselves. In some cases, IC devices are mounted on a film substrate to constitute driver electronics parts to be mounted on a transparent substrate or to be connected between a transparent substrate and a printed circuit board.
No matter which mounting method is employed, it is difficult to use solder in connecting electrodes on the side of the driver electronics parts to electrodes on the side of the substrate, which are formed in an extremely fine pitch. Therefore, ACF has been resorted to in the art in order to electrically connect the electrodes on the side of the driver electronics to the electrodes on the side of the substrate in a secure and reliable manner. ACF has conductive particles or grains dispersed in a binder resin with sticky and electrically insulating properties. After bonding AFC on a transparent substrate, driver electronics parts are bonded thereon by a TAB (Tape Automated Bonding) operation, and heat and pressure are applied thereto to electrically connect the electrodes on the side of the TAB-mounted electronics parts to the electrodes on the side of the transparent substrate through the conductive particles in ACF.
Generally, ACF is laminated to a predetermined thickness on one side of a liner tape through a releasing layer. The AFC tape is wound on a supply reel, and a fore end portion of the AFC tape is drawn out from the supply reel and bonded on a transparent substrate by the use of a bonding means.
The AFC tape which is wound on a supply reel is limited in length. Therefore, as soon as an AFC tape supply reel is consumed completely, it has to be replaced by a fresh supply reel. At an AFC tape feeding station, a supply reel is set on a reel support shaft, and, when consumed completely, dismantled therefrom and replaced by a fresh supply reel. The reel replacing job is not completed simply by setting a fresh supply reel on the reel support shaft. It also involves a job of drawing out a fore end portion of the AFC tape on the newly set supply reel and connecting same to a bonding means. Namely, actually the reel replacement job involves a tape end connecting job in addition to reel replacement.
Heretofore, the reel replacing and tape end connecting jobs have relied on manual labor of an operator despite the fact that these jobs are troublesome and time consuming. Especially, since the ACF tape has an adhesive surface on one side, an operator is required to pay great attention not to touch the adhesive surface. Namely, the operator has to handle the ACF tape very carefully in reeling off a fore end portion of the ACF tape from a fresh supply reel and connecting same to a bonding means even if it takes a relatively long period of time.
Of course, the operation of mounting driver electronics parts on a substrate is suspended during the reel replacement and the tape end connecting operation, resulting in great time losses. Besides, in order to minimize the time losses, the operator needs to watch the progress of a tape feeding operation and to replace a supply reel by a fresh one in a good timing, that is to say, as soon as the tape from one reel is completely consumed. Accordingly, the operator has to stand by exclusively for this purpose from well before a time point when tape supply from a currently operating supply reel comes to an end. As a result, the operational efficiency is deteriorated considerably by the reel replacements because the operator cannot do other jobs during each standby period.
Especially, as a result of recent progresses and improvements in automatic mounting apparatus for electronic circuitry parts, there has been a trend toward speeding up the tact time of electronic parts mounting operations, consuming the ACF tape of each supply reel in a shortened period of time and as a result necessitating to replace the supply reel at a higher frequency. It is a paramount requisite to shorten the time period of the reel replacements in order to shorten a time period for mounting each electronic part.